AMS Skirt induced Print failure

I’m slowly getting into multi-color prints but came across a failure point in the very beginning - The AMS Skirt.

When printing Multicolour, AMS/ The slicer adds a skirt around the first model after a colour change. (at least what i believe is the reason) The problem with this is that it’s not a single layer high, but a multiple layer high Skirt, without the bed changing its Z position. The slicer only shows the skirt as a single layer.

So the printer is printing a multi-layer high skirt without actually lowering the bed. As a result, it prints in itself, which eventually causes the skirt to come off and stick to the nozzle.



I paused the Printer, removed the skirt that came off and resumed the print. It printed 2 more skirt layers and then went over to the actual model.

Yikes!

I have been printing for a few decades, but my first Bambu has yet to arrive (next week!), so I don’t know much about the slicer yet.

I would hope there is a way to turn off having any skirt at all. If so, that’s what I would do. I almost never print with skirts when using other 3D printers.

Sorry I can’t be more helpful yet, but hopefully you can figure out how to turn off the skirt and, even though it is technically just a work around, at least it will get you back to printing.

Though it is probably worth letting Bambu Labs know about this in case it is happening to others as well and they need to update software.

There is, for the outer skirt

grafik

The model skirt is part of the multi color printing and not affected by the “normal skirt” settings above.

Here is how it looks with the “general” skirt disabled. Leaves only the skirt after a color change. I’m fine with it, if it would actually only print a single layer of it and not pile up like in the video

Hmm…

Maybe there is a setting somewhere else to tell it not to prints skirts during color change? Or maybe if you use a purge tower then it won’t make skirts?

I hope there is a way to turn that off. I don’t recall having seen skirts on other people’s multi color time lapses. I certainly don’t want to print with skirts once my AMS gets here. :frowning:

Sorry I can’t be more helpful yet. Hopefully someone else who knows more will be able to help.

A purge tower won’t be generated, even if enabled.

I do seem to have found the solution and it is indeed a bug.

If i slice it with Skirt “Off” - no skirts will be generated
if i slice it with skirt “on” - it will generate the skirt around all models and those per model skirts.
if i THEN untick skirts again and let it slice, then the skirt around all models will disappear but the per model skirt still exists. The only fix would be to reload the project so the plate is loaded with skirt not enabled.

I recorded it to make it more clear. Watch in Fullscreen to see it better.

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That definitely looks like something they need to bug fix in the software.

Glad you were able to get it working!

Did you look at the per part settings? That should help the debugging. No need to actually print. Just look at the slice of each part and tailor individual parts’ settings.

i did. Nothing related to skirts in the per model settings.

Weird. I am a bit puzzled as to why the purge tower is disabled manually though.

With filament change enabled, the nozzle wiping should occur somewhere. There’s a rather interesting thread on Purge-to object in Bambu Studio, but if you are not going down that route, it does make sense that the slicer wants to create at least a nozzle wipe skirt. That would be an intentional feature rather than a bug.

Try slicing with a purge tower or print object-by-object.

it is sliced object by object and purge tower was enabled but not generated.

Weird.

Since there’s one extra skirt per color, I would still guess that the missing prime tower is the principal reason though. Since I usually print layer by layer though, with lots of purging :roll_eyes:, I am not experienced with the approach though.

That skirt height and blobby quality is rather suboptimal.

Since I am not experienced enough, perhaps another helpful soul would be able to shed light on this? Maybe @Olias? Always good advise and insights from your posts. Especially, but not only, on slicing.

I was able to recreate the same issue. Steps I did were

  1. Create by-object print - with 3 objects of two different colours. (GYG)
  2. Sliced - no skirts
  3. Saved Project - pre-skirt
  4. Turned on one skirt loop
  5. Sliced
  6. Turned off skirt loop
  7. Sliced - single skirt still present on one of the objects - in my case the 3rd object - the 2nd green object - in my case the printing was. Green Object, Yellow Object, Green Skirt then object.
  8. Saved Project with skirt error in it
  9. Loaded back the first ‘pre- skirt’ project
  10. Then loaded back ‘skirt error’ project -
  11. The error seemed to go away for me - so it doesn’t seem to be getting saved - so I think the work around is to save the project, then reload it back again.

I am really glad the BL prints seem to be happy to work mostly without skirts around parts - as I have often had trouble with them detaching on past printers.

PS/. Re prime towers - they only get created for ‘by layer’ prints as far as I know - due I guess to the slicer wanting to keep the printing of each object nicely isolated on the bed. i.e. If there was a single prime tower it would need to keep jumping back and lowering the Z height between objects requiring colour changes.

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I’m so glad you have that on camera!! I experienced the exact same issue yesterday.

I also opened a case on Github, maybe (if you haven’t done yet) you could add your story.

I had 16 objects, grouped into 4 and was printing by object in order to print each colored group separately. As I had some minor underextrusion at the beginning of each new color (due to a missing purge-block) I added the skirt and this glitch happened.

I was not yet able to reproduce the error… later on I’ll give the one (explained above) a try.

I can add some of my findings to it later!

It actually just happened to me again… GRRR…!!!

I wanted to reproduce it by following the steps above and noticed that on the print I got running the preview shows the exact same behavior… and yes… the skirt is messed up and glued to the print. Damnit!! I did not expect that to happen again.

It clearly has to do with the option “by object” that’s for sure.

This time I was prepared and got it on camera:

and yes… I should maybe increase the purge going from red to white now that I noticed that as well. ^^